This enable two things:
1. Follow global clockvm setting, without adjusting qrexec policy.
2. Avoid starting clockvm by arbitrary VM.
FixesQubesOS/qubes-issues#3588
clock synchronization mechanism rewritten to use systemd-timesync instead of NtpDate; at the moment, requires:
- modifying /etc/qubes-rpc/policy/qubes.GetDate to redirect GetDate to designated clockvm
- enabling clocksync service in clockvm ( qvm-features clockvm-name service/clocksync true )
Works as specified in issue listed below, except for:
- each VM synces with clockvm after boot and every 6h
- clockvm synces time with the Internet using systemd-timesync
- dom0 synces itself with clockvm every 1h (using cron)
fixesQubesOS/qubes-issues#1230
